Estimator module incompatible with FeOS 0.9

[Darz2]

Hi,

Thanks for this wonderful package. I have been using it for a while for computing phase equilibria and the corresponding interfacial tensions of multicomponent mixtures. However, in v0.9, I found that the estimator module in crates/feos/src/estimator/ is present in the source code but fails to compile due to compatibility issues between v0.8 and v0.9.

I use Python bindings. I tried to enable the estimator by:

Adding estimator = [] to [features] in crates/feos/Cargo.toml
Adding "estimator" to the all_models array
Adding pub mod estimator to crates/feos/src/lib.rs
Running maturin develop --release to create the Python bindings of all models

However, the build failed due to several compilation errors. I believe all these are due to the update from v0.8 to v0.9. Some of the error to mention are:

1. Missing 'Arc' imports in multiple files
2. State::critical_point function signature has changed (now expects 5 arguments instead of 4)
3. DensityInitialization::None no longer exists
4. State::new_npt function has changed (Arguments are incorrect)

Thanks in advance

Kind regards,
Darshan

[g-bauer]

Hi Darshan,

you are right, we did not include the estimator feature in the latest version. It might come back in a future version but for now, if you want to use v0.9, the simplest solution is to build your own cost function in Python.

If you need help with that, we can provide an example notebook.

[Darz2]

Hi Gernot Bauer,

Thanks for the clarification and update.
Building the cost function sounds like a good workaround for now. I would really appreciate it if you could share the example notebook. Thanks again for your support.

[g-bauer]

I added a simple example for methane with data from the NIST Webbook as gist here. It does not properly handle issues with convergence (if they appear) but I think it shows the setup. If you include surface tensions into the optimisation, it might be worth doing it in two steps (first step without, second step including sft's).

Let me know if you have further questions.